Hydraulic hoist for dump bodies



NOV. 26, 1935. P BRlcK HYDRAULIC HOIST FOR DUMP BODIES 2 Sheets-Sheet 1Filed April 21, 1934 Nov. 26, 1935. P. A. BRICK HYDRAULIC HOIST FOR DUMPBODIES 2 Sheets-Sheet 2 Filed April 21, 1934 ing the travel of thevehicle carrying said body and Patented Nov. 26, 1935 UNITED STATES2,022,181 HYDRAULIC HOIST FOR DUMP BODIES Perry A. Brick, Galion, Ohio,

Perfection Steel Body Company,

a corporation Application April 21,

1 Claim.

My invention involves certain improvements in hydraulic hoist mechanismsof the type which are commonly used today for incorporation inautomotive vehicles or trucks for the purpose of lifting dump bodiesmounted upon the truck frame.

The special construction of hydraulic hoist employed by me utilizes acylinder for the reception of the motive fluid, preferably oil, pistonmeans mounted in said cylinder and connected by its piston rod; to anoperating head exterior to the cylinder, together with linkageconnections intermediate said operating head and the body which is to beraised and lowered, whereby the lifting pressure derived from the fluidin the cylinder may be transmitted through the links to the said bodyfor elevating the latter. The operating head according to myconstruction is equipped with rollers to travel upon tracks or railsmounted on the frame of the vehicle in the back and front movement ofthe head for the elevating and lowering movements of the body as causedby the link connections therewith.

Involved in my invention is a peculiar arrangement and mounting for therollers carried by the operating head such that the thrust of the linkswhich converge toward each other at the points of connection with thehead will in no way be transmitted to the rollers so as to interferewiththe freedom of action of the latter in their travel upon therails ortracks provided therefor. Additionally .I provide a. special mountingfor the cylinder and piston actuating unit such that the cylinder has acertain amount of freedom to rotate about the longitudinal axis thereofand such that there is provided what may be termed a three-pointsuspension mounting for the cylinder whereby to relieve the cylinderas-- sembly from any strains that might be set up incident to theweaving of the truck frame-under unequal stresses or pressures that maybe received thereon in the operation of elevating and lowerthe dump bodyor such as may be caused by cylinder assembly over uneven surfaces.

Another feature of my invention comprises a special form of stop anddetent devices controlling the extent of movement of the operating headby which the lifting links are actuated and likewise having a detainingfunction in reference to preventing liability of unauthorized or liftingmovement of the operating head off of the operating track due to thetendency of the dump body to shift beyond its pivot in the dumpingoperation, Liability of bending of the piston rod for actuating theoperating head is thus avoided.

Still another feature of the invention resides in the provision in thecylinder assembly of a special spring arrangement cooperating with theassignor to The Galion, Ohio,

1934, Serial No. 721,824

actuating piston for the operating head in such a manner, as totend tomove the dump body downwardly at the end of the elevating structure ofthe piston and head, the said spring having suficient tension to startthe body back to its lowered position when the cylinder pressure isrelieved. Since the body is usually raised-almost to the vertical toafford a proper clearing or dumping action of the contents thereof,devices of this type prior to my invention have a tendency for the bodyto remain in its upraised position after the pressure is relieved andthis tendency is obviated by me through the employment of the springmeans above referred to.

A thorough understanding of the features of novelty of the presentinvention will be had upon reference tothe following description and theaccompanying drawings, in which,-

Figure l is a. perspective View of an automo- 'tive vehicle frame anddump body construction 2 adapted thereto, illustrating the mechanism ofthe invention in combination therewith.

' Figure 2 is a side elevation of the parts illustrated' in Figure 1,the dump body omitted and the cylinder parts being broken away and shown25 in section. I

Figure 3 is a top plan view of a somewhat fragmentary nature as regards.the frame construction, illustrating the parts shown in Figure 2 morefully. p

Since the invention is applicable to various types of chassis or framestructures of dumping trucks, the frame construction per se is not amaterial feature of the invention save as it is combined with the partsof the cylinder, operating head, lifting links, and track arrangementsthat will be more fully set forth shortly. In the drawings the dumpingbody illustrated is designated A and may be any one of many differenttypes commonly used. It is pivotally mounted 40 accordingto thisinvention may be conventional 45 save and except in respect to theemployment of longitudinal rails or track members 4, the said trackmembers being connected at the front of the chassis with a. cross member5 and at the rear portion of the chassis with a cross member fi locatedsome distance in advance of the axis means 3 previously referred to.

At the front portion of the chassis or frame of the vehicle is disposedthe pump 1 which may be of a known type adapted to be operated bysuitable shaft means partially shown at 8, the latter to be connectedwith the power take-off adapted to be attached to the truck transmissionmeans, this feature of construction not, however, being a part of thepresent invention, as

previously indicated. From the pump 1 an intake pipe 9 leads to thefront end of the cylinder assembly which includes the cylinder I0, saidpipe 9 being connected with a coupling supported by a trunnion I Icarried by-and rigidly fastened to the head at the high pressure end ofthe cylinder. The trunnion II is hollow so that the pipe line 9 mayconduct the oil therethrough into the high pressure end of the cylinderI as will be obvious. However, it is notable that the trunnion II issubstantially concentric with the axis of the cylinder I 0 and free toturn a bearing on the cylinder supporting member I 2 which takes theform of an angle plate rigidly mounted upon the front ends of the trackmembers 4 and frame sides 2, the vertical flange of said angle platehaving the said bearing formed therein. Thus the high pressure end ofthe cylinder II] has a one-point suspension or supporting mounting. Atthe rear end thereof, the cylinder I0 is carried by special separatebrackets is fastened to the inner sides of the track members 4 atcorresponding outer ends and fastened to the rear cylinder head I 4 attheir corresponding inner ends, as well seen in Figure 2, the parts 52and I3 affording a three-point suspension mounting for the cylinder III.

In the cylinder I0 is mounted the pressure operated piston I5 and thispiston has the customary piston rod I6 which projects through the rearend or head I4 of the cylinder and carrying thereon exterior tothecylinder the hollow sleevelike operating head I I. This operatinghead I! is mounted between the lifting links I8 that connect with aroller shaft I9 upon which rollers 20 are mounted, said rollers beingfree to travel longitudinally of the track members 4. It is notable thatthe links I8 converge forwardly toward their points of connection withthe roller shaft I9 so that the thrust of the said links toward eachother is transmitted directly to the crosshead I1 and shaft I9, leavingthe rollers 20 entirely free to take care of the vertical component ofthe thrust action. In other words, there is no tendency on the part ofthe thrust component ofthe links I8 to interfere with the free turningof the rollers 20 and the stress set up in the shaft I is purely shearas compared with prior devices of this type, wherein the lifting linksemployed are so'attached usually outside of the rollers as to producebending stresses in the shaft means that corresponds with the shaft I9of the present invention, not to mention addition thereto,disadvantageous thrusts against the ends of the rollers, all of whichdifficulties are obviated by the present improvements.

It is notable that near the rear end of the tracks 4 and carried by thecross member 6, is a combined stop and detent member 2|, the verticalportion of which is the stop element, and the upper curved hook 2la ofwhich constitutes the detent member. The operating head I! is adapted toabut with the stop member 2| when the dumping body A has been elevatedto its highest point for dumping, the movement of the cross'headrearwardly for dumping purposes being thus limited. At the same time thehook portion 2 la of the stop member 2| engages over the operating headI! and thus the'part 2I2Ia serves not only to limit the piston travelunder the pressure actuation of the piston I5, but also prevents the'crosshead I! from being lifted off the track members 4 by reason of thetendency and rotatively mounted in said cross plate, and bracketssecured to the spaced'members aforeof the body A to continue movementrearwardly beyond its limit of elevating action under the actuatingforce of the piston I5 and pressure fluid in the cylinder I 0.

Within the cylinder I0 and mounted upon the piston rod I6 at the frontside of the piston I5 is a coiled spring 22 which encircles the pistonrod. This spring moves rearwardly with the piston I 5 and piston rod I6during the pressure stroke for elevating the'dump body A and the rearend of the 10 spring 22 finally abuts with the head I4 at the rear end.of the cylinder I0 and becomes compressed during the final movement ofthe dump body A in reaching its dumping limit of travel.

Since the weight of the dump body is not always sufficient to start thebody back to its original or lowered normal position when the cylinderpressure in the cylinder I0 is relieved, it will be seen that thecompressed spring 9 performs an actuating function upon relief of saidpressure such as will furnish sufficient force to move the piston i5forwardly as soon as the lifting pressure is released, thereby topositively cause the dump body-A to start its downward movement at suchtime.

.By reason of the three-point suspension or mounting of the cylinderassembly described, it is evident that strains will not be set up in thecylinder assembly by reason of any weaving or distortion of the truckframe in the practical use of the device of the invention.

At a predetermined point in the rearward movement of the piston I5 actedupon by the fluid pressure medium, said piston closes the low pressureport 23 near the rear end of the cylinder 35 with which port connectsthe low pressure pipe line 24. This action of the piston in closing theport 23 limits the stroke or travel of the piston and of coursecorrespondinglylimits the forward dumping movement. of the dump body A.There- 40 afterthe pressure on the-front side of the piston may bereleased in the customary way. to provide for the downward movement ofthe dump body in an obvious manner.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent of the United States, is

In a dumping vehicle of. the class described,

the combination of a dump body, a chassis upon which the dump body issupported, mechanism for raising and lowering the dump body, includinglifting links, a hydraulic'cylinder and piston assembly connected to thelifting links comprising a cylinder, a piston therein, a piston rod eX-tending from the. piston through an end of the cylinder, an operatinghead connected with said piston rod and attached to the lifting linksfor actuation thereof, spaced members carried by the chassis betweenwhich the cylinder, piston and piston rod assembly is disposed, a crossplate carried by said spaced members, a hollow trunnion to receive apressure line connection carried by one end of the cylinder at the axisof the latter

